Introduction

Mercury is a naturally occurring element often found at low concentrations and with low toxicity in various natural environments.  Mercury enters terrestrial and aquatic systems through atmospheric deposition: processes such as refining and burning fossil fuels and incinerating municipal waste concentrate mercury while volcanic eruptions can naturally release mercury into the atmosphere.  Many forms of mercury can affect the health of humans and wildlife resulting in neurological, digestive, endocrine and skin disorders. Unfortunately, high levels of mercury are present in many ecosystems, connected by air, water, and the organisms that inhabit them. 

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